Current meteorological forecasts from models including GFS and ECMWF consensus place Istanbul's overnight low near 18°C on September 26, driven by moderate northeasterly winds, partial cloud cover, and stable high pressure yielding minimal overnight cooling. This aligns with the market's elevated 18°C probability at 25.5% while the near-even split between ≤13°C (50%) and ≥23°C (49%) reflects trader hedging amid typical short-range model spread and potential for minor steering pattern shifts. Historical late-September baselines for the region average 15–17°C lows, but recent ensemble runs show tight clustering around 17–19°C with low precipitation risk, leaving resolution sensitive to final observational data from local stations.